The present application relates to wearable wireless electronic devices, and in particular, to tag-like or patch-like wireless devices that can adhere to human skin.
Wearable patches or tags can communicate with smart phones and other devices using WiFi, Bluetooth, or NFC technologies. Near Field Communication (NFC) is a wireless communication standard which enables two devices in a short range to establish a communication channel within a short period of time through radio waves in the 13.56 MHz frequency range. NFC can be a useful technology for data transfer between two devices in close proximity to one another. Because it needs the two devices to be in close proximity to one another (less than 10 cm), it is more secure than other wireless technologies like Bluetooth and Wi-Fi. Hence, it can be seen as an easy and secure tool for establishing quick two-way connections for data transfer. NFC is a two-way communication tool, one of the devices/cards can have a passive NFC tag that can reduce the cost and still behave in the same way as any other RFID tag. NFC uses passive energy that is collected through active electromagnetic coupling from the reader devices, so it brings another benefit of these NFC tags do not need a battery in its system that simplify the product design and make disposable product possible.
This communication standard is being increasingly adopted for use in wireless transactions, including money transfer, loyalty coupons, gift cards, transit passes, tickets, etc. Mobile handset manufacturing companies are increasingly integrating NFC hardware in their phones. For example, the 2014 CES badges employed NFC technology and have resulted in shorter lines, more badge functionality, and greater ease of use for attendees and exhibitors. NFC has also been increasingly used in the fields of medical devices, electronic health records, as well as wearable tagging devices.
In other scenarios, long communication distance is required, such as >10 meters. Without tapping the reader device in the close range NFC patch from time to time, data can be collected automatically and continuously with least operator interference. In such cases, Bluetooth and WiFi are a proper option with a 1.5V or 3V battery supply.
Wearable tag (or patch) is an electronic tag that can be worn by a user. Wearable patch is required to directly stay on user's skin and function for an extended period of time from hours to months. A wearable patch can contain a micro-electronic system and can be accessed using NFC, Bluethooth, WiFi, or other wireless technologies. For example, an authentication wearable tag can be used to recognize a user's smart phone for authentication purpose. It can also be integrated with different sensors for other purposes such as vital signs monitoring, motion track, skin temperature measurements and ECG detection.
Despite initial development efforts, conventional wearable devices still face several drawbacks: they may not provide adequate comfort for users to wear them; they may not stay attached to user's body for the required length of time; they are usually not aesthetically appealing.
Another drawback of conventional wearable patches is that the rigid polymer substrate does not allow much breathability to the skin. The build-up of sweat and moisture can cause discomfort and irritation to the skin, especially after wearing it for an extended period of time. In addition, their rigid substrates are very difficult to conform to curved surfaces.
Moreover, conventional wearable devices are often not robust enough to sustain repeated elongations during the movements of the body that the wearable patches are attached to. Under stress, different layers in wearable patches can break or delaminate rendering the patches inoperable.
On the other hand, conventional electrodes for measuring human organ electrical activities are usually bulky and not stretchable or flexible. The data collection process is usually at the cost of life quality for users.
There is therefore a need for a device for measuring human organs' electrical signals which are durable and comfortable for users to wear.